| Men's singles | |
|---|---|
| 2021 Nottingham Open | |
| Champion |  Frances Tiafoe |
| Runner-up | Denis Kudla |
| Score | 6–1, 6–3 |
Dan Evans was the defending champion [1] but lost in the quarterfinals to Denis Kudla.
Frances Tiafoe won the title after defeating Kudla 6–1, 6–3 in the final. [2]
Dan Evans (quarterfinals) Frances Tiafoe (champion)
Andreas Seppi (quarterfinals)
Kevin Anderson (quarterfinals) Mackenzie McDonald (first round) Denis Kudla (final)
Damir Džumhur (first round)
Kamil Majchrzak (semifinals)| Semifinals | Final | ||||||||||||
| 6 | Denis Kudla | 6 | 1 | 78 | |||||||||
| 8 | Kamil Majchrzak | 4 | 6 | 66 | |||||||||
| 6 | Denis Kudla | 1 | 3 | ||||||||||
| 2 | Frances Tiafoe | 6 | 6 | ||||||||||
| Q |  Marius Copil | 3 | 2 | ||||||||||
| 2 | Frances Tiafoe | 6 | 6 | ||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1/WC | D Evans | 4 | 77 | 77 | |||||||||||||||||||||||
 T Kokkinakis | 6 | 61 | 65 | 1/WC | D Evans | 78 | 77 | ||||||||||||||||||||
| Q | M Ebden | 6 | 6 | Q | M Ebden | 66 | 64 | ||||||||||||||||||||
| WC | R Peniston | 4 | 4 | 1/WC | D Evans | 4 | 6 | 4 | |||||||||||||||||||
| A Bolt | 5 | 6 | 3 | 6 | D Kudla | 6 | 1 | 6 | |||||||||||||||||||
| L Broady | 7 | 3 | 6 | L Broady | 6 | 3 | 62 | ||||||||||||||||||||
 T Macháč | 3 | 6 | 4 | 6 | D Kudla | 3 | 6 | 77 | |||||||||||||||||||
| 6 | D Kudla | 6 | 4 | 6 | 6 | D Kudla | 6 | 1 | 78 | ||||||||||||||||||
| 3 | A Seppi | 77 | 6 | 8 | K Majchrzak | 4 | 6 | 66 | |||||||||||||||||||
 Zh Zhang | 64 | 2 | 3 | A Seppi | 6 | 64 | 6 | ||||||||||||||||||||
| T Fabbiano | 65 | 63 |  A Hoang | 4 | 77 | 2 | |||||||||||||||||||||
| A Hoang | 77 | 77 | 3 | A Seppi | 6 | 2 | 3 | ||||||||||||||||||||
| M Polmans | 610 | 6 | 3 | 8 | K Majchrzak | 4 | 6 | 6 | |||||||||||||||||||
| Q | A Vukic | 712 | 4 | 6 | Q | A Vukic | 7 | 610 | 4 | ||||||||||||||||||
 P Gunneswaran | 0 | 0r | 8 | K Majchrzak | 5 | 712 | 6 | ||||||||||||||||||||
| 8 | K Majchrzak | 6 | 0 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 7 | D Džumhur | 4 | 6 | 1 | |||||||||||||||||||||||
| Q | M Copil | 6 | 4 | 6 | Q | M Copil | 6 | 6 | |||||||||||||||||||
| Q |  B Gojo | 3 | 712 | 66 |  S Ofner | 4 | 4 | ||||||||||||||||||||
| S Ofner | 6 | 610 | 78 | Q | M Copil | 77 | 711 | ||||||||||||||||||||
| M Cressy | 4 | 77 | 3 | 4 | K Anderson | 64 | 69 | ||||||||||||||||||||
| L Rosol | 6 | 65 | 6 | L Rosol | 3 | 4 | |||||||||||||||||||||
| WC | J Clarke | 3 | 60 | 4 | K Anderson | 6 | 6 | ||||||||||||||||||||
| 4 | K Anderson | 6 | 77 | Q | M Copil | 3 | 2 | ||||||||||||||||||||
| 5 | M McDonald | 3 | 5 | 2 | F Tiafoe | 6 | 6 | ||||||||||||||||||||
 E Donskoy | 6 | 7 | E Donskoy | 77 | 77 | ||||||||||||||||||||||
| B Nakashima | 6 | 6 | B Nakashima | 63 | 62 | ||||||||||||||||||||||
 M Vilella Martínez | 3 | 2 | E Donskoy | 64 | 6 | 3 | |||||||||||||||||||||
| F Gaio | 2 | 3 | 2 | F Tiafoe | 77 | 2 | 6 | ||||||||||||||||||||
 I Marchenko | 6 | 6 | I Marchenko | 5 | 65 | ||||||||||||||||||||||
 M-A Hüsler | 3 | 4 | 2 | F Tiafoe | 7 | 77 | |||||||||||||||||||||
| 2 | F Tiafoe | 6 | 6 | ||||||||||||||||||||||||
This was the first edition of the tournament.
Noah Rubin was the defending champion but lost in the first round to Peter Polansky.
Daniel Evans was the defending champion but lost in the second round to Peter Polansky.
Kyle Edmund was the defending champion but chose not to defend his title.
This was the first edition of the tournament.
John Isner was the defending champion and successfully defended his title, defeating Ryan Harrison in a rematch of the 2017 final, 5–7, 6–3, 6–4.
Frances Tiafoe was the defending champion, but lost in the first round to Dan Evans.
Daniil Medvedev was the defending champion, but chose not to participate this year.
Mitchell Krueger was the defending champion but lost in the third round to Denis Kudla.
Kyle Edmund was the defending champion but chose not to defend his title.
Hubert Hurkacz was the reigning champion from when the tournament was last held in 2019, but chose not to participate this year.
This was the first edition of the tournament, which was primarily organized to compensate for the cancellation of Asian tournaments in 2021 due to the COVID-19 pandemic.
Tommy Paul defeated defending champion Denis Shapovalov in the final, 6–4, 2–6, 6–4, to win the singles tennis title at the 2021 Stockholm Open. It was Paul's first ATP Tour title.
Aslan Karatsev defeated Andy Murray in the final, 6–3, 6–3 to win the men's singles title at the 2022 Sydney Tennis Classic. This was Murray's first ATP final since he won the 2019 European Open.
Dan Evans was the defending champion but chose not to defend his title.
Frances Tiafoe was the defending champion but chose not to defend his title.
Nick Kyrgios defeated Yoshihito Nishioka in the final, 6–4, 6–3 to win the men's singles tennis title at the 2022 Washington Open. It was his second Washington title, following 2019. Kyrgios saved five match points en route to the title, in the quarterfinals against Frances Tiafoe. He also did not drop serve during the tournament.
Taylor Fritz defeated Frances Tiafoe in the final, 7–6(7–3), 7–6(7–2) to win the singles tennis title at the 2022 Japan Open.
Dan Evans defeated Tallon Griekspoor in the final, 7–5, 6–3 to win the men's singles tennis title at the 2023 Washington Open. It was his second ATP Tour singles title.
Tommy Paul defeated Marcos Giron in the final, 7–6(7–3), 5–7, 6–3 to win the singles tennis title at the 2024 Dallas Open. It was his second ATP Tour title.